package de.mpiwg.itgroup.annotationManager.restlet;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.Hashtable;

import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attribute;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;
import javax.naming.directory.SearchControls;
import javax.naming.directory.SearchResult;
import javax.security.auth.Subject;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.login.AppConfigurationEntry;
import javax.security.auth.login.Configuration;
import javax.security.auth.login.LoginContext;
import javax.security.auth.login.LoginException;

import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.restlet.Application;
import org.restlet.Context;
import org.restlet.Request;
import org.restlet.Response;
import org.restlet.Restlet;

import org.restlet.data.ChallengeScheme;
import org.restlet.data.ClientInfo;
import org.restlet.ext.jaas.JaasVerifier;
import org.restlet.routing.Router;
import org.restlet.routing.Template;
import org.restlet.routing.TemplateRoute;
import org.restlet.security.ChallengeAuthenticator;
import org.restlet.security.MapVerifier;
import org.restlet.security.User;
import org.restlet.security.Verifier;

import com.sun.org.apache.xalan.internal.xsltc.runtime.Attributes;
import com.sun.security.auth.login.ConfigFile;




public class RestServer extends Application {

	
	private ChallengeAuthenticator authenticator;
	private CallbackHandler callbackHandler;

    /** Erzeuge einen Authenticator
     * @return
     */
    private ChallengeAuthenticator createAuthenticator() {
        Context context = getContext();
        boolean optional = true;
        ChallengeScheme challengeScheme = ChallengeScheme.HTTP_BASIC;
        String realm = "Annotation Service";

        // MapVerifier isn't very secure; see docs for alternatives
        //MapVerifier verifier = new MapVerifier();
        //verifier.getLocalSecrets().put("user", "password".toCharArray());

        JaasVerifier verifier = new JaasVerifier("BasicJaasAuthenticationApplication");
        
        
        Configuration jaasConfig;
        jaasConfig = createConfiguration();
        
        
		verifier.setConfiguration(jaasConfig);
        verifier.setUserPrincipalClassName("com.sun.security.auth.UserPrincipal");
        
        ChallengeAuthenticator auth = new ChallengeAuthenticator(context, optional, challengeScheme, realm, verifier) {
            @Override
            protected boolean authenticate(Request request, Response response) {
                if (request.getChallengeResponse() == null) {
                    return false;
                } else {
                    return super.authenticate(request, response);
                }
            }
        };

        return auth;
    }

	protected Configuration createConfiguration() {
		Configuration jaasConfig;
		URI confUri;
		try {
			confUri = new URI("file:///etc/jaasAuth.conf"); //TODO shoould be configurable
		} catch (URISyntaxException e) {
			e.printStackTrace();
			confUri = null;
		}
		
		jaasConfig= new ConfigFile(confUri);
		return jaasConfig;
	}

	public RestServer(Context parentContext){
		super(parentContext);
		
		Logger rl = Logger.getRootLogger();
		BasicConfigurator.configure();
		rl.setLevel(Level.DEBUG);
		
		
	}
	
	public synchronized Restlet createInboundRoot(){
		 this.authenticator = createAuthenticator();

		
		Router router = new Router(getContext());
		
		router.attach("/annotations",AddAndSearchAnnotations.class);
		router.attach("/search",AddAndSearchAnnotations.class); // annotator api askes for different uris for search and adding
		router.attach("/dummy",Dummy.class);
		
		authenticator.setNext(router);
	    return authenticator;

		
		
	}
	
	 public boolean authenticate(Request request, Response response) {
	        if (!request.getClientInfo().isAuthenticated()) {
	            authenticator.challenge(response, false);
	            return false;
	        }
	 
	        if(request.getClientInfo().getUser()==null) //FIXME sometimes ist authenticated true, but no user
	        {
	        	authenticator.challenge(response, false);
	            return false;
	        }
	        return true;
	    }

	public boolean authenticate(String username, String password,Request request) {
		LoginContext lc;
		
		try {
			Configuration conf = createConfiguration();
			
			lc = new LoginContext("BasicJaasAuthenticationApplication", null, new MyCallBackHandler(username,password),conf);
			lc.login();
		} catch (LoginException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return false;
		}
		
		Subject subject = lc.getSubject();
		ClientInfo clientInfo = new ClientInfo();
		User user = new User(username);
		clientInfo.setAuthenticated(true);
		clientInfo.setUser(user);
		
		request.setClientInfo(clientInfo);
		return true;
	}

	public String getUserNameFromLdap(String creator) {
		String retString=creator; // falls nichts gefunden wird einfach den creator zurueckgeben
		Hashtable<String,String> env = new Hashtable<String,String>();
	    String sp = "com.sun.jndi.ldap.LdapCtxFactory";
	    env.put(javax.naming.Context.INITIAL_CONTEXT_FACTORY, sp);

	    String ldapUrl = "ldap://ldapreplik.mpiwg-berlin.mpg.de/dc=mpiwg-berlin,dc=mpg,dc=de";//TODO should go into config file
	    env.put(javax.naming.Context.PROVIDER_URL, ldapUrl);

	    DirContext dctx;
		try {
			dctx = new InitialDirContext(env);
		} catch (NamingException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
			return retString;
		}

	    String base = "ou=People";

	    SearchControls sc = new SearchControls();
	    String[] attributeFilter = { "cn", "mail" };
	    sc.setReturningAttributes(attributeFilter);
	    sc.setSearchScope(SearchControls.SUBTREE_SCOPE);

	    String filter = "(uid="+creator+")";

	    try {
			NamingEnumeration<SearchResult> results = dctx.search(base, filter, sc);
			while (results.hasMore()) {
			  SearchResult sr = (SearchResult) results.next();
			  javax.naming.directory.Attributes attrs = sr.getAttributes();

			  Attribute attr = attrs.get("cn");
			  retString=(String) attr.get();
			}
		} catch (NamingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	    
	    try {
			dctx.close();
		} catch (NamingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	    return retString;
	}

}